Just by the weight of sheer probability, it's most likely that Canon will just reuse an older sensor such as the one from the 90D on an R7 if it's ever released.
Looking at all the RF camera bodies released, other than the two most expensive bodies, they all use repurpoed sensors from previous DSLR camera bodies.
2022 Canon EOS R3 - new
24.1 MP stacked BSI CMOS sensor
2020 Canon EOS R5 - new
45MP CMOS sensor
2020 Canon EOS R6 - reused EOS 1D X Mark III 20MP CMOS sensor
2019 Canon EOS RP - reused EOS 6D Mark II DSLR 26MP CMOS sensor
2018 Canon EOS R - reused EOS 5D Mark IV DSLR 30MP CMOS sensor
If there are possible cost cutting measures, they will likely be taken by Canon. See the post below:
Canon’s Imaging Unit Grew, Profits Shrunk on Costs, ‘Various Measures’ Coming
The company said it expected double-digit profit growth in future quarters “as negative impact of cost increase is absorbed through various measures.”
In news that will hearten Canon shooters, the firm indicated in its quarterly results that parts availability is improving. In news that probably won't hearten